On Tuesday, Gordon Brown announced his government's support for a new generation of nuclear power plants. In so doing, he casts himself in the role of the bold leader, taking tough decisions for the common good.

Certainly the Sun has bought it wholesale, shrieking: "Britain's security will be in peril if we continue to rely on Russian despot Vladimir Putin or Middle Eastern states for our gas and oil."

Obviously, this is so much rubbish and it won't deal with the real policy decisions and proper investment necessary within the next 10 years to bridge the energy gap and set us on course for massive emissions reductions over the coming decades. Indeed, there are some colossal lies at the heart of the government's nuclear fundamentalism.

Con one: nuclear will protect us from Russian despots and unstable Middle Eastern states. Let's be clear. Electricity is not the same as energy. The lion's share of our energy demand is for heat and transport. With all due respect to the Sun, although nuclear power currently accounts for about one-fifth of UK electricity generation, that is less than 4% of our total energy demand.

So how does nuclear electricity improve security of gas or oil supply? Of our oil and gas consumption, 86% is for purposes other than producing electricity. Most of the gas we use is for heating and hot water, or for industrial purposes. Virtually all oil is used for transport.

In this context, nuclear power - which can only generate electricity - is irrelevant. The real answer to lessening our oil dependence includes improved vehicle efficiency, improved public transport systems and reducing the need to travel, especially for business by using new technology like video conferencing.

The Russian "peril" is a load of jingoistic claptrap. The truth is that - unlike the rest of Europe - the UK has no proper long-term gas storage facilities to cover supply or price fluctuations. And most of our gas supplies, according to the government, will come from more not fewer countries as new gas fields are exploited.

Con two: nuclear power will bridge the energy gap. Over the next few years, several existing nuclear and coal plants are set to close. This is the "energy" (ie electricity) gap. Government figures suggest that this gap equates to about one-third of our current electricity supply. The challenge is to bridge this gap in a way that allows us to meet our legitimate energy needs and sets us on course for massive emissions reductions over the coming decades.

Even leaving aside the intrinsic problems with nuclear power (for instance, its costly and dangerous legacy of radioactive waste), nuclear electricity cannot solve our energy problems. For starters, not a single nuclear power station will come into operation over the next decade. Indeed the UK government itself has estimated that a new build programme of up to ten stations could not deliver in full until at least 2025. So even notionally, nuclear will make no contribution to our electricity until years after the "energy gap" needs to be dealt with.

The real answer? There are now dozens of studies by government and energy industry bodies showing how this scale of electricity generation could be met through many different cleaner alternatives, including combined heat and power (CHP), using fossil fuels more efficiently and cleanly, and renewable electricity generation such as wind, wave and tidal power. A portion of the gap could be closed through energy efficiency alone - delivering substantial economic savings at the same time.

Last month, the government announced the next stage of offshore wind development in the UK, which, if delivered, will fill two-thirds of the energy gap. Indeed, as Gordon Brown himself acknowledged when I questioned him late last year, the UK has committed to generating around 40% of our electricity from renewables by 2020.

So if the prime minister is telling the truth, there is no energy gap: not only will the UK become a world leader in clean energy, but even the bogus case for nuclear evaporates.

Con three: it's the only way to reduce our climate change emissions. According to the government's own sustainable development commission even if the UK built ten new nuclear reactors, nuclear electricity could only theoretically deliver a 4% cut in carbon emissions some time after 2025.

The real solutions to the energy gap and climate change are available now. Energy efficiency, cleaner use of fossil fuels, renewables and state of the art decentralised power stations like they have in Scandinavia.

These options are challenging and require support and concerted government effort to deliver (just as nuclear power requires), but given that support, this mix has the potential to deliver reliable low-carbon energy more quickly, more cheaply, more effectively and more realistically than nuclear. The strategy is also safe and globally applicable, unlike nuclear.

The real threat from Gordon Brown's brand of nuclear fundamentalism is that if cash and political energy get thrust at nuclear power, these technologies will be strangled. Then we really will need to mind the gap.